The present invention relates to a private branch exchange system such as a key telephone system, and particularly to a multimedia private branch exchanger capable of handling video signals, computer data and the like as well as voice signals and a private branch exchange system employing CTI (Computer Telephony Integration).
Many key telephone systems have been employed in office buildings and company offices. Recently, as an extension-type system thereof, a multimedia-applicable key telephone system has been proposed, which processes not only voice signals at telephone terminals, but also video signals and computer data at videophone terminals and personal computers.
However, in a conventional system of this kind, for example, a standalone router is provided separately from a main key telephone apparatus so that a data terminal connected to a LAN (Local Area Network) is connected to the main key telephone apparatus via the standalone router. Therefore, the standalone router and an interface unit dedicated for the main device need to be prepared for connection to the LAN, which increases the user""s economic burden.
On the other hand, employment of a CTI (Computer Telephony Integration) has been reviewed for constitution of the key telephone system. The CTI allows the main key telephone apparatus to be connected to a server computer or personal computers, and the computers to process the parts of the exchange of the main key telephone apparatus and storage and working of the voices and data, etc. The CTI can realize a high-performance system without enhancing the processing performance of the main key telephone apparatus.
Generally, the main key telephone apparatus is designed with high reliability so as to be operated under the unmanned control for a long time. However, since a cheap widely used computer such as a personal computer is used as the CTI computer of the key telephone system, it can be well expected that the CTI computer may often lapse into an uncontrollable state such as malfunction, or abnormality may occur in an air-cooling fan, a hard disc, a power supply, etc. In these cases, if a maintenance person or an operator is stationed near the CTI computer, he can immediately finish the malfunction program and restart the operation of the computer, or stop the CTI computer to disconnect it from the main key telephone apparatus. Generally, however, a maintenance person or an operator is not stationed. If the CTI computer is abnormally operated, the processing ability of the system is not only lowered, but also the abnormality in the CTI computer influences the main key telephone apparatus, which may cause the system down. Therefore, effective measures against such operational abnormality have been expected.
The conventional multimedia-applicable key telephone system described above has a problem that the router dedicated for accommodation of the LAN and the interface unit dedicated for the main device need to be installed and thereby the manufacturing cost of the system may be increased.
In addition, in a case where the router is a general dial-up router, there are problems that (1) a new ISDN line other than the main key telephone apparatus needs to be drawn or an ISDN extension line interface unit dedicated for the key telephone need to be prepared; and (2) when the battery at the power failure is backed up, an uninterruptible power supply UPS needs to be prepared to enhance reliability.
Further, when the CTI is carried out, there is also a problem that solutions to the operational abnormality of the computer have not been established.
The present invention has been accomplished by considering the above-described circumstances, and its first object is to provide a multimedia private branch exchanger which can accommodate the LAN while restricting the manufacturing costs of the system as much as possible.
The second object of the present invention is to provide a private branch exchange system which can effectively respond to abnormality in operations of the CTI computer.
In order to achieve the first object, there is provided a multimedia private branch exchanger, comprising: a line interface unit having a function of controlling communication with extension line telephone terminals; a router unit having a function of controlling communication with data terminals to be connected to the local area network; an office line interface unit provided commonly to the line interface unit and the router unit, and having a function of controlling communication with an external communication network; and a switching unit for selectively connecting the line interface unit and the router unit to the office line interface unit, on the basis of a request for setting a call.
The present invention has also a characteristic of comprising a power supply unit provided commonly to the line interface unit, the router unit, the office line interface unit and the switching unit, and supplying the power necessary for their respective operations from the power supply unit to each of the units.
That is, in the present invention, the router unit for connection of the local area network is built in the exchanger, this router unit has the only interface function with the local area network, and the office line interface unit and the power supply unit which have been provided in the exchanger are used as the office line interface unit and the power supply unit provided normally in a general dial-up router.
Therefore, according to the present invention, the standalone router or the general dial-up router does not need to be provided separately from the exchanger. In addition, the router unit of the present invention is not only built in the exchanger, but also the office line interface function and the power supply unit which have been provided in the exchanger are commonly used as the office line interface unit and the power supply unit which are to be provided in the router unit. As a result, a system which is of high reliability, a comparatively small size and low manufacturing costs, can be provided.
The present invention has also a characteristic of comprising, in the router unit, a protocol converting unit for connecting the data terminals directly connected to the LAN, to the office line interface within the exchanger. In this structure, when a plurality of data terminals are connected to the local area network, the entire data transfer between the data terminals and the respective unit in the exchanger can be subjected to the interface process in the router unit. As a result, the function of the interface with the exchanger does not need to be provided at each of the data terminals and thereby the burden on the data terminal users can be reduced.
Further, the present invention has also a characteristic of comprising a hub in the router unit and connecting a plurality of local area networks or data terminal devices via the hub.
On the other hand, in order to achieve the second object described above, there is provided a private branch exchange system, comprising an exchanger for accommodating a plurality of extension lines and at least one office line and having various functions concerning exchange between the extension lines or between the extension liens and the office line; and a CTI computer for carrying out part of the functions of the exchanger, and the system comprises, in the CTI computer, means for monitoring abnormality in its own device, and means for informing the exchanger of abnormality monitor results obtained by the abnormality monitoring means, and also comprises, in the exchanger, means for receiving the abnormality monitor results from the CTI computer, means for discriminating abnormality on the basis of the abnormality monitor results received by the abnormality receiving means, and abnormality response means for optionally disconnecting the CTI computer from its own device on the basis of discrimination results of the abnormality discriminating means.
The abnormality monitoring means monitors at least one of abnormality in a temperature inside the CTI computer, abnormality in the power supply, abnormality in operations of a cooling device and abnormality in operations of the computer.
Therefore, according to the present invention, when abnormal rise of the temperature, abnormality in the power supply, operational abnormality in the cooler, or operational abnormality in operations of the program occurs in the CTI computer, results of the detection are informed from the CTI computer to the exchanger. In response to this information, the abnormal state is discriminated by the exchanger. If there is a danger of malfunction in the CTI computer, the CTI computer is disconnected. As a result, the operational abnormality in the CTI computer does not influence the exchanger and thereby the system down can be preliminarily prevented.
Moreover, the present invention has also a characteristic of further comprising, in the CTI computer, means for monitoring recovering conditions of its own device from the abnormality, and means for informing the exchanger of the recovery results monitored by the recovery monitoring means; and further comprising, in the exchanger, means for receiving recovery monitor results from the CTI computer, means for discriminating recovering conditions on the basis of the recovery monitor results received by the recovery receiving means, and means for restoring the connection with the CTI computer on the basis of the discrimination results of the recovery discriminating means.
According to the present invention, when the CTI computer is recovered from the operational abnormality, the connection between the exchanger and the CTI computer is automatically restored. Therefore, for example, when the CTI computer, which is abnormally operated temporarily, returns to the normal condition, or when the CTI computer returns to the normal condition after the parts of the CTI computer are exchanged, the connection between the exchanger and the CTI computer can be restored without waiting for the restoring operation to be made by a maintenance person.
Furthermore, the present invention has also a characteristic of allowing the exchanger to inquire the CTI computer about operated conditions of the CTI computer; and compulsorily resetting the CTI computer when a predetermined response to the inquiry is not sent from the CTI computer to the exchanger, for example when no response or abnormal command is returned.
Therefore, even when the CTI computer cannot be restored by its own self, for example, when there is malfunction in the program of the CTI computer, the CTI computer can be reset by the exchanger and the operated state of the CTI computer can be restored to the normal condition.
In addition, as described above, when the cooler is broken, abnormality occurs in the power supply, or there is malfunction in the program, in the CTI computer, the information indicative of the abnormal condition may be transferred from the exchanger to the extension line terminals or a relay station and, for example, the information may be displayed on a LCD or voice messages may be made so as to inform the user or a relay station operator of the information. Thus, the user or the relay station operator can immediately understand that there has been operational abnormality or malfunction in the program, in the CTI computer, and can thereby quickly take measures such as the restoring operations.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.